Well drilling apparatus



Dec. 12, 1933. J. G. BURMxsT WELL DRILLING APPARATUS Filed Nov. 16, 19312 Sheets-Sheet l INVENTQR John G. Burmlst WITNESS BY @05M FIG. i.

ATTORNEY Dec. 12, 1933. J. G, BURMIST WELL DRILLING APPARATUS Filed Nov.16, 1931 2 Sheets-Sheet 2 INVENTOR WITNESS BY @.M

ATTORNEY Patented Dec. 12, 1933 PATENT OFFICE WELL DRILLING APPARATUSJohn G. Burmst, Philadelphia, Pa., assignor to Victor I. Zelov,Philadelphia, Pa., trustee Application November 16, 1931 Serial No.575,378

13 Claims.

My invention relates to earth-boring apparatus and it has for an objectto provide improved means of controlling the pressure applied to theboring implement or drill.

In the boring of wells, more particularly oil wells, rotary drills orboring implements are frequently used. It is common practice to suspendthe boring apparatus from a rig by means of a cable, the cable beinganchored at one end to the rig, passing through sheaves of uppen andlower blocks, and passing from the upper block to a raising-and-loweringor winch drum. The upper block is supported by the rig and the lowerblock is connected to the head construction of l5 the drillingapparatus. Tension devices are ordinarily arranged in the cable betweenthe upper block and the rig and in the cable between the upper block andthe drum, and the operator controls the drum to keep the tensiondifference as nearly the same as possible to control the net pressureapplied to the drill cutter. In accordance with my invention, the drumis not used as a part of the means for obtaining control of the cuttingpressure but merely to hoist and lower the cutting apparatus asrequired, the cutting pressure being controlled hydraulically, wherebysuch pressure is maintained continuously and uniformly with boring andunaffected by normal winch operation in raising and lowering. Thehydraulic means is operative to impart a pressure lift to the boring ordrilling aggregate opposed to the Weight thereof and the fluid pressuremay be varied to obtain a desired weight preponderance to give thecutting pressure, and the hydraulic means is constructed and arranged toprovide for lowering of the cutting aggregate as material is bored awaywith maintenance of uniform cutting or boring pressure. Hence myinvention makes unnecessary thecable tension devices and the indicatingapparatus ordinarily used in connection therewith and it removes fromthe operator the responsibilityof controlling the drum yso as to keepthe correct relation of tension in the two 5 end portions of the cable.Therefore, it is a furf ther object of my invention to provide boringapparatus having these features and advantages. These and other objectsare effected by my invention as will be seen from the followingdescription and claims taken in connection with the accompanyingdrawings in which:

Fig. l is a side elevational View showing my improved drillingapparatus;

Fig. 2 is an enlarged sectional view of the head construction;

(Cl. Z55-19) Fig. 3 is a View showing a semi-automatic form of myinvention; and

Figs. 4 and 5 are detail views.

Referring now to the drawings more in detail,

I show a drilling rig 10 supporting a rotary drill tube, indicatedgenerally at 11, the latter having the usual rotary cutter (not shown)at its lower end. Water under pressure is supplied through the drill orcutter tube to flush borings and cuttings away from the cutter. The tube11 is ro tated in the usual way by the turning gear at 12.

A head 14 is arranged at the upper end of the tubular drill shaft 11,the head and tube being suspended by a cable 15 anchored at 16 to therig 10, passing through sheaves of upper and lower blocks 17 and 18 andgoing from the upper block 17 to the winch or hoisting and lowering drum19. The upper block 17 is suspended from the top of the rig and thecutting apparatus including the head 14 is suspended from the lowerblock 18. Therefore, the drum may be operated to raise and lower thecutting or boring apparatus. In accordance with my invention, the head14 incorporates hydraulic means for maintaining a desired boring ordrilling pressure, thereby making unnecessary tension devices associatedwith the cable and very careful opeation of the drum to keep the cuttingpressure as nearlyuniform as possible.

The head 14 embodies a body construction 20 provided with a cylinder 21within which is arranged a piston 22 connected to the upper end of thedrill or boring tube 11. Fluid, for example, oil, under desired pressureis supplied to the cylinder space below the piston; and, by controllingthe supplied pressure, the force acting below the piston 22 may be madegreat enough to lift the drilling or boring aggregate including thepiston 22, the drill or boring tube 11, and other parts unitarytherewith, the pressure force may be made to exactly counterb'alance theweight of the aggregate, or the weight of the aggregate may preponderateover the pressure force to a desired extent to give the proper cutterpressure. In operation, pressure is increased below the piston 22 untilthe counterbalancing point is reached, the pressure being shown on asuitable indicator or gage 24 in communication with the lower end of thecylinder 21, and then the pressure is reduced sufficiently to give thedesired weight preponderance forfthe cutting pressure, the gage beingobserved soV that a predetermined reduction in pressure suicient for thepurpose may be effected.

Fluidfor exerting pressure beneath the piston 22 is supplied by a pump25, through a supply line 26, to the pressure control device ortransformer, at 27, incorporated in the body construction 20. Thetransformer, at 27, supplies fluid to or exhausts iluid from the lowerportion of the cylinder 21 by way of the passage 28. Exhaust and leakagefluid is drained by the return line 29 back to the tank 30 for the pump25.

The control device Jor transformer, at 27, embodies a lower valvecylinder 32 and an upper cylinder 33 of larger diameter. The valvecylinder has a lower pressure port 34 communicating with the pressuresupply line 26 and an upper exhaust port 35 connected to the drainpassage 36 leading to the drain or return line 29. A piston valve 37 tsthe cylinder 32 and it is provided with a port 38 arranged to have itsupper edge just lap the lower edge of the exhaust port 35 and its loweredge just lap the upper edge of the pressure port 34 when the valve isin cut-off position.

The piston valve port 38 is connected by the passages 39 and 40 with theupper cylinder 33 below the piston 42 connected to the valve 37 andfitting the cylinder 33. The lower ends of the cylinders 33 and 21 areconnected by the passage 28 already referred to. The effect of fluidpressure acting below the piston 42 is to move the latter and the valve37 upwardly to cut off the supply of fluid under pressure from the line26 and then to place the lower portions of the cylinders 21 and 33 incommunication with the exhaust. y

Spring means is arranged above the piston 42 for opposing fluid pressureacting therebelow, and the spring means is adjustable to give a desiredcounterbalancing fluid pressure. As shown, a spring 44 is arranged abovethe piston 42, the lower end of the spring abutting a thrust bearing 45,which, in turn, abuts the upper end ofthe piston 42, and the upper endof the spring abutting the follower 46 held in position by a screw 47threaded to the cylinder cover 48. The upper end of the screw 47 isprovided with an actuating handle 49 and a jam nut 50 holds the screwin\ adjusted position. The spring force acting down on the piston 42may, therefore, be variedas desired, and, whatever the spring force is,it is balanced by an equal fluid pressure force acting below the piston42. l

Assuming that the weight or gravity force of the cutter aggregate is :z:pounds and that y pounds is the desired drilling or cutting pressure,then a lift or fluid pressure force of :n minus 1l pounds must beapplied to the aggregate. To effect this relation, the operator adjuststhe spring force until the fluid pressure force acting below the piston22 balances the weight of the cutter aggregate, the gage pressuresumcient for this being observed; and then the screw 47 is backed to anextent suicient to reduce the fluid pressure to an amount `correspondingto a: minus y pounds lift, whereupon the desired lift relation to give ypounds cutting pressure is made effective and maintained by the pressuretransformer, at 27. Spinning motion is preferably imparted to the piston42 and the valve 37 to overcome static friction and to make the devicemore sensitively responsive to changes in pressure. To this end, I showpassages 52 in the piston 42 for supplying fluid under pressure frombelow the piston to the reaction jets of nozzles 53 above the piston.InK

this connection, it will be observed that leakageIVY of fluid as well asfluid utilized by the spinning jets tends to reduce the pressure belowthe pistons 22 and 42; however, any such tendency immediatelyl resultsin downward movement of the piston 42 and of the valve 37 underinfluence of the spring 44 to place the lower portions of the cylinders21 and 33 in communication with the pressure port 34. In practice, thepressure port 34 communicates with the lower portions of such cylindersto 8L keep the pressure in balancing relation with the spring 44.

In practice, the drill tube 11, except for parts immediately adjacent tothe head construction, at 14, is made in lower sections 55 (one beingshown) and an upper section 55a, the latter having a slidable andnon-rotatable connection with the turning gear 12, as is well known inthe art. In operation, when the cutter aggregate has been loweredincident to cutting or boring for about the length of the tube section55a, the latter is then detached from the adjacent section 55 and anadditional section 55 is inserted in the aggregate, whereupon theapparatus will again be ready for drilling or boring.

As shown, the drill or cutter aggregate includes, in addition to thecutter and the tube sections 55 and 55a, the piston 22 and a dependingtubular member 56 unitary with the piston and extending below the bodyconstruction 20. A water tube 57 extends through the body construction20, the piston 22, and the tubular member 56, the upper end of the tubebeing secured to a supply connection 58 and the lower end thereofextending below the tubular extension or member 56. A yoke couplingmember 60 is connected to the lower end of the tubular member 56 and ithas a lower tubular portion 61 provided with a coupling end 62 forattachment to the tube section 55a. An upper gland 63 prevents leakageof oil from between the tubular member 56 and the telescoping water tube57 and a lower gland 64 between the water tube 57 and the tubularportion 61 of the yoke prevents leakage of water. Also the yokeconstruction and the spaced glands prevents possible admixture of waterwith the oil.

As material is cut away by the drill or cutter, the latter should belowered with maintenance of the desired drill or cutter pressure. Toprovide for the continuous maintenance of the de- 9 sred cutterpressure,the piston 22 has a range of movement downwardly relatively to thecylinder 21, and, when the limit of this range is reached, the cylinder21 is lowered relatively to the piston. y

The body construction 20 and the cylinder 21 are lowered by controllingthe drum 19 to pay out'cable 15; and, as hereinafter pointed out,control f the drum 19 to secure intermittent lower'- ing of the bodyconstruction 20 and the cylinder 130 21 may be automatic orsemi-automatic. Even though the cylinder volume below the piston 22 isincreased when the cylinder is lowered, the predetermined lift pressurewill be maintained, for, as soon as the volume starts to increase, thepressure drops and the spring 44 moves the piston 42 and the pistonvalve 37 down to increase the supply of fluid under pressure to theunderside of the piston 22. These operations would be concurrenty withjust sufficient pressure drop to secure operation of the piston valve,so that for all practical purposes the pressure or lift ismaintainededuring the time that the cylinder 2l is lowered. l

In Fig. 1, I show a full automatic arrangement for lowering the bodyconstruction 20 and the cylinder 21, the automatic operation beingeffected by a make-and-break switch, at 65, and the winch or hoistingmotor 66. When the cutter aggregate moves down incident to cutting andits tive to the cylinder 21, the switch, at 65, is

` closed and the motor is rendered eifective to pay out cable to lowerthe body construction 20 and the cylinder 21; and, whenthe latterreaches the lower limit of its movement relative to the piston 22, theswitch, at 65, is opened, whereupon the body construction and itscylinder are held in iixed position until the piston 22 again moves downincident to cutting until the limit of downward movement thereofrelative to the cylinder is reached.

The tube 57 is restrained from rotation with the tube system proper bythe pivoted links 68 and 69, the link 68 having a hinge connection 70with respect to the water inlet member 58 and the link 69 being hingedat 71 to the body construction cover 48.' The linkage holds the tubularelements 57 and 58 against rotation and permits of movement of thelatter with the cutter aggregate relatively to the body construction 20.A thrust bearing 72 prevents relative axial movement of the water tube57 and the piston 22.

The make-and-break limit switch, at 65, preferably includes a rockermake-and-break contact element 73 pivotally connected to a rod 74 havingadjustable upper and lower stops 75 and 76 thereon. An actuator 77,movable axially with the cutter aggregate but restrained from rotarymovement by the linkage just referred to, moves between the abutments.When the lower limit of movement of the piston 22 relative to thecylinder 21. is reached the actuator 77 contacts the lower abutment 76to tilt the rocker 73 downward to close the circuit for the winch ordrum motor, whereupon the body construction and the cylinder 21 arelowered until the upper abutment 75 contacts with the actuator and therocker is tilted upward to open the motor circuit.

In Fig. 3, I show a semi-automatic embodiment of my invention, which issimilar to Fig. 1 except that the limit switch, at 65a, controls analarm system instead of the winch or drum motor and the operator isguided by the indicator or alarm system in operating the winch or drum.For example, I show a suitable signal or alarm 80, which becomeseffective when the limit of downward movement of the piston 22 relativeto the cylinder 21 is reached and it remains effective until theoperator operates the drum to lower the body construction 20 and thecylinder 21 relative to the piston 22 and when the limit of the lattermovement is reached the signal or alarm circuit is broken by opening ofthe switch, at 65a.

scribed for exerting lift on the cutter aggregate should be ineffective,then the apparatus is capasion difference to keepl the cutting pressureas uniform as possible. With no fluid in the cylinder 21 sustaining thepiston 22, the latter rests on the thrust bearing 83 carried by thebottom of the cylinder provided by the body construction 20, the latter,of course, being carried by-the cable suspension. The thrust bearing 83permits of ready relative rotation of the cutter aggregate with respectto the body construction of the head,'at 14. Y

From the foregoing, the operation of my improved well boring apparatuswill be apparent. Obtaining and maintaining the cutter pressure ismerely a matter of fluid pressureV adjustment and requires n'o furtherattention on the part of the operator. The arrangement may be fullyautomatic or semi-automatic, and, in either case, the lift pressurehaving been initially adjusted, 85 the operator does not have to concernhimself with maintenance of the cutting pressure. Furthermore, theimprovements do not prevent the operation of the apparatus in the usualway by controlling the cable drum in accordance with the tensiondevices.

While I have shown two embodiments of my invention, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various other changes and modifications, withoutdeparting from L4the spirit thereof, and I desire, therefore, that onlysuch limitations shall be placed thereupon as are imposed by the priorart or as are specically set forth in the 'appended claims.

What I claim is:

1. Inboring apparatus, a rotary boring aggregate having a piston, a bodymember having a cylinder fitting the piston, means for supporting thebody member, and means for maintaining a predetermined liquid pressurein the cylinder below the piston vso that the weight ofthe aggregatepreponderates over the liquid pressure force to an extent sufficient to(give a desired, boring pressure, said means including uid pressuresupply andv exhaust ports, a valve member movable in one direction toeffect communication of the cylinder with the pressure supply port andmovable in the other direction to eiect communication ofthe cylinderwith the exhaust port. an abutment face subject to cylinder pressure formoving the valve member in .the direction to eifect communication of thecylinder with the exhaust port, and a spring whose force opposes thefluid pressure force exerted on the abutment face. e

l2. In boring apparatus, a rotary boring aggregate including a piston, acylinder tting the piston, suspension means for the cylinder, means forsupplying liquid under predetermined pressure to the cylinder below thepiston to exert Alift;- ing force on the aggregate to reduce to apredetermined extent the effect of theweight of the aggregate inproviding cutting pressure, means operable in response to downwardmovement of Y the piston relative to the cylinder to a predeterminedextent to lower the cylinder, and means operable in response to relativelowering of the cylinder with respect to the piston to a predeterminedextent to limit lowering of the cylinder.

3. In boring apparatus, a rotary boring aggregate including a piston, acylinder for the piston, suspension mechanism for raising `and loweringthe cylinder and including an operating motor, means for supplyingliquid to the cylinder below the piston including means for maintainingthe pressure uniform and providing for variable piston displacement withapproximate maintenance of the uniform pressure, means responsive todownward movement of the piston relative to the cylinder to apredetermined extent to render the motor effective to lower thecylinder, and means responsive to lowering of the cylinder relative tothepiston to a predetermined extent to stop the motor.

piston, admission and exhaust ports for the cylinder space below thepiston, a valve controlling communication of said space with theadmission Y and exhaust ports, means responsive to pressure in saidspace for moving the valve to establish communication of the space withthe exhaust port, spring means for moving the valve to establishcommunication of said space with the admission port, means for supplyingliquid under pressure to the admission port, and suspension means forthe cylinder. n

5. In boring apparatus, a rotary boring aggregate including a piston, acylinder for the piston, suspension means for the cylinder, admissionand exhaust ports for the cylinder space below the piston, means forsupplying liquid under pressure to the admission port, a valve movablein one direction to effect communication of said space with theadmission port and movable in the other direction to eilectcommunication of said space with the exhaust port, means responsive topressure in said space to move the valve to effect communication withthe exhaust port, spring means acting in opposition to the pressureresponsive means and effective when it overcomes the pressure responsivemeans to move the valve to eiect communication with the admission port,and means for adjusting the compression of the spring means.

6. In boring apparatus, a boring aggregate including a piston, acylinder for the piston, suspension means for the cylinder, a pistonvalve cylinder having pressure and exhaust ports, means for supplyingliquid under pressure to the pressure port, a piston .valve fitting the'valve cylinder and having a passage communicating with the space of saidcylinder below the piston, a pressure responsive element connected tothe piston valve and responsive to pressure in said space for moving thepiston valve to place its passage in communication with the exhaustport, and spring means acting on the piston valve in opposition to thepressure responsive means for moving the piston valve to place itspassage in commimication with the pressure port.

7. The combination as claimed in claim 6 with means forvarying thecompression of the spring means in order that the pressure of liquid inthe space ofthe cylinder below the piston may be varied:

8. In boring apparatus, a rotary boring aggrel gate including a piston,a cylinder for the piston, suspension means for th cylinder includingmeans for raising Iand lowering the cylinder, means for supplying liquidunder pressure to the space of the cylinder below the pisto andincluding valvev means responsive to pressure in said space above apredetermined pressure to exhaust liquid from the space to limit thepressure therein and responsive to decline in pressure in said spacebelow the predetermined pressure to increase the pressure supply toprevent lowering of pressure in said space, means responsive to loweringof the piston relative to the cylinder to a predetermined extent torender the raising and lowering means eil'ective to lower the cylinder,and means responsive to lowering movement of the cylinder relative tothe piston to a predetermined extent to stop the lowering movement ofthe raising and lowering means.

9. In earth-boring apparatus, a rotary boring aggregate including apiston; a cylinder within which the piston is disposed; suspension meansfor the cylinder; fluid pressure supply and exhaust ports; a valvemember cutting off communication of the cylinder space below the pistonwith the exhaust and uid pressure supply ports when it is inintermediate position, movable in a first direction from intermediateposition to place 'saidcylinder space in communication with the exhaustport, and movable in a second direction from intermediate position toplace said cylinder space in communication with the pressure supplyport; and means for controlling the position of the valve memberincluding an abutment face subject to cylinder iluid pressure force formovingv the valve member in said lrst 'direction and a spring for movingthe valve member in said second direction.

10. The combination as 'claimed in claim 9 with means for adjusting theforce of the spring.

11. The combination as claimed in'claim 9 with manual means foradjusting the compression ot the spring and with a gage for indicatingthe cylinder space pressure.

12. In boring apparatus, a rotary cutter aglgregate, suspension meansfor the aggregate including a cylinder, a piston connected to theaggregate and arranged in the cylinder, a source of uid under pressure,valve mechanism including movable valve means for controlling theadmission of fluid from said source to the space of the cylinder belowthe piston and for controlling the exhaust of iluid from such space,means responsive to uidpressure in said cylinder for moving the movablevalve means to ad-

